Cooling device for telephone-transmitter.



c. B. BGNE'R & J G. HOL-MSTILEIM. COOLING DEVICE FOR TELEPHONE TRANSMITTEBS.

APPLICATION FILED AUG.18, 1909.

Patented Apr. 18, 1911.

' To all whom it may concern:

Arn 1 rica.

cAzan EMI-L Ecrnnn, ors'rooKHonM, AND JOE-IAN ennnannomvi'srnon, or sALrsJov 1 sToRANGniv, sWEDE.N. ,f

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Specification of Letters Patent. i Patented Apr. 18, 1911.

Application-filed August 18, 1909. Serial No. 513,410.

Beit 'known that we, CARL EM n Eemin, a subject of the King of-Swede'n, and resi dent of Blekingegatan 653 Stockholm, in the Kingdom of Sweden, and-JoHAN GUN NA R HoLMsTnoM, a subject of the King of Sweden, and resident of Saltsjti-Storangen, in the Kingdom of Sweden, have invented certain new and useful Improvements in Cooling Devices for Telephone-Transmit.-

ters, of which the following is a specification,

. panying drawing.

i The condition 'for attaining reference being had therein to the accoma telephone transmitter practical in every respect, which, when speaking toward the same, effects great variations in the electric energy, con-.

sists in great variations in the resistance being'-'effected and in the transmitter being able to endure strong current. Great variations in the resistance are effected if a diaphragm is employed which is strained from itscenter outward and to which one or more electrodes owing to which the properties of the" strained diaphragm are maintained even when a strong current passes throug'hthe transmitter. tions effected in the diaphragm by the heat generated by the current shows that the diaphragm loses. the tension atand immediately in the vicinity of the place or places,

where it supports an electrode owing to a local generating of heat. The heat removes.

the concentrated oscillating action of the electrode proper effected by the straining of the diaphragm. The said injurious influenceof the heat on the. strained diaphragm is re moved by providing at or in the Vicinity of the diaphragm a cooling device. Such a device very suitable in the said respect is shown in the accompanying drawing. in a ,cross A closer study of the altera-.

section-in Figure 1 and a plan View in Fig. 2. Fig. 3 is a cross section of a form of t'he invention.

The diaphragm is jammed between the rings 2 and 3 and strained by the ring 4, which is forced inward by suitable means as for instance screw bolts l0, with thumb nuts 11, until a suitable-straining has been imparted to the'whole diaphragm. In order the center part of the uniformly strained diaphragm a body 5 cylindric or of any other suitable shape is fixed to the center part of the diaphragm and carries the electrode 6. In order to preventthe heat generated at the electrode 6 from being transmitted to the strained diaphragm 1 a preferably spiral pipe 7 is provided close by the diaphragm and adapted. to contain a coolingliquid pass- .ing through the same. 8 is the inlet opening and 9 the outlet opening of the pipe. Owing to the bodyfi, which is made of steel or any other hard and durable material in order to modified j to make effective the forcible oscillations at v provide the stability necessary for the transv mitting of the oscillations of-the diaphragm 1 to the electrode 6, the source of heat is located at some distance from the diaphragm, which fact will assist the cooling pipe in its functioning. Although the spiral shape of the pipe 7 is the most suitable any other-suitable shape may be used. I y Thebody 5 maybe hollow, as shown in Fig. 3. and filled with a cooling liquid. The invention may be modified also in such way that a small receptacle or box 12 is fixed to the center of the diaphragm 1, as shown by dotted lines in Fig. 3, which box preferably communicates at its bottom; with the hollow body 5 or is made integrajl with the same, and is filled with cooling liquid; a L

Having now described our invention, wha

we claim as new and desire to secure by Let-- ters Pa tent is: v

1. Ina telephone transmitter the com bination of a strained diaphragm and a pipeprovided in the vicinity of thefdiaphragin and containing a cooling medidm, substantially as described and for the purpose set forth. i Y

2. In a telephone transmitter the combination of a strained diaphragm, a spiral pipe provided in the vicinity of the diaphragm and containing a cooling liquid i gned our names in the presence of two subpassing through the same. h scribing Witnesses. 3. In a telephone transmitter t 8 combination of a strained diaphragm and are- I 5 ceptacle containing a cooling liquid and provided at the diaphragm, substantially as Witnesses:

described and for the purpose set forth. Aix N'ASEiDnRSTREiM,

In witness Where0f, we have hereunto ROBERT APELGREN. 

